KR930012145B1 - Brightness signal reproducing circuit and method of different system - Google Patents

Abstract

The circuit has a frequency doubling information detector receiving the chrominance signal and the luminance signal from the luminance signal input section for detecting frequency doubling information in the synchronisation signal to control a selection stage. The latter supplies the luminance signal to two alternate processing circuits dependent on whether or not the frequency doubling information is detected, coupled via a further selection stage to a luminance signal output stage.

Description

Luminance signal reproducing circuit and method for maintaining compatibility in reproduction between different image systems

1A and 1B are block diagrams schematically showing a recording circuit and a reproducing circuit of a general video signal recording and reproducing apparatus, respectively.

2A and 2B are block diagrams schematically showing the recording circuit and the reproducing circuit of the improved video signal recording and reproducing apparatus to which the circuit of the present invention is applied, respectively.

3 is a block diagram schematically showing a luminance signal reproduction processing circuit which maintains compatibility during reproduction between different image systems according to the present invention.

4 is a detailed block diagram of the circuit shown in FIG.

* Explanation of symbols for main parts of the drawings

1: Y / C separation part 2: Emphasis part

3: FM modulator 4: Record amplifier

5, 27: recording head 6, 28: playback head

7: standard luminance signal reproducing unit 8: limit

9: FM demodulator 10: Deemphasis

11, 36: composite video signal generator 21, 31, 70: A / D conversion unit

22: Y / C separation unit 23: Adaptive de-emphasis

24: frequency folding unit 25: frequency overlap information recording unit

26, 35, 110: D / A converter 32, 80: frequency overlap information detector

30, 81, 801: de-emphasis unit 83: memory or frame averaging unit

85: reproduction light unit 33, 90: frequency unfolding unit

92: spatial reconstruction section 93: complex luminance signal generator

34, 100: adaptive re-emphasis 700: luminance signal input unit

800: frequency overlap information detection unit 802: first selection unit

900: conventional method signal processing unit 1000: improved method signal processing unit

1001: second selection unit 1002: luminance signal output unit

The present invention relates to a circuit and a method for maintaining compatibility in reproducing between different video signal recording and reproducing methods.

The present invention is recorded by a conventional video signal recording and reproducing method, particularly in a system disclosed in Application No. 07 / 569,029, “Improved Video Signal Recording System”, filed in the United States of America on August 17, 1990 by the applicant. A luminance signal reproducing circuit and method for reproducing a video tape while maintaining compatibility are provided.

In general, in the conventional video signal recording / reproducing apparatus, as shown in FIGS. 1A and 1B, the luminance signal Y separated by the Y / C separation unit 1 when the composite video signal is recorded is represented by an emphasis unit ( 2) to emphasize the high frequency component of the luminance signal. At the time of reproduction, the de-emphasis unit 10 processes the high frequency component of the luminance signal emphasized at the time of recording to the original signal. This will be briefly described with reference to FIGS. 1a and b.

According to FIG. 1A, the recording circuit of the conventional video signal recording / reproducing apparatus separates the luminance signal Y through the Y / C separating section 1 into which the video signal is input, and the separated luminance signal Y is emulated. After being emphasized in the passage part 2, it is supplied to the FM modulator 3.

The signal modulated from the FM modulator 3 is amplified by the recording amplifier 4 and recorded on the video tape by the recording head 5. At this time, although not shown in the drawing, the color signal separated by the Y / C separator 1 is synthesized and recorded with the luminance signal processed by the color signal processor. On the other hand, as shown in FIG. 1B, the reproducing circuit of the conventional video signal recording and reproducing apparatus reproduces the video signal recorded on the video tape through the reproducing head 6, and then receives the luminance through the standard luminance signal reproducing section 7. Play the signal. The reproduced luminance signal Y is limited by the limit section 8 and then demodulated in the FM demodulation section 9. This demodulated luminance signal is also supplied to the de-emphasis unit 10 to restore the signal emulated in the recording circuit to the original signal. Next, the composite video signal generation unit 11 synthesizes the color signal from the color signal reproduction processing unit (not shown) and the de-emphasized luminance signal to output the composite video signal (Y + C).

However, as shown in FIGS. 2A and 2B, the recording and reproducing circuits of the improved video signal recording and reproducing apparatus to which the circuit of the present invention is applied include the conventional recording and reproducing circuits shown in FIGS. 1A and 1B. Unlike in the case of the circuit, when the composite video signal is recorded on the video tape, the overlapping high-frequency luminance signal passes through the adaptive de-emphasis unit 23 and is subjected to frequency folding. Part 34 is to pass through. This will be described briefly.

According to FIG. 2A, the composite video signal Y + C is separated from the luminance and color signals by the Y / C separation section 22 via the A / D conversion section 21. The separated luminance signal Y outputs a frequency overlapped signal from the frequency folding section 24 via the adaptive de-emphasis section 23, and the frequency overlapping information recording section 25 separates the frequencies superimposed upon reproduction. The overlapping information is inserted into the horizontal sync signal Hsync. Next, the luminance signal into which the frequency overlap information is inserted is subjected to the D / A conversion by the D / A conversion section 26 to a video tape through the recording head 27 together with the color signal through a series of steps not shown. Will be recorded.

Meanwhile, as shown in FIG. 2B, the luminance signal is reproduced by the standard luminance signal reproducing section 29 through the reproducing head 28 in the reproducing circuit of the improved video signal recording and reproducing apparatus to which the circuit of the present invention is applied. Next, although not shown in FIG. 2A, the de-emphasis unit 30 multiplies the high-frequency signal of the luminance signal in order to restore the pre-emphasized luminance signal at the time of writing. Although the de-emphasized luminance signal is not shown in the drawing, the FM demodulated, and when the FM demodulated luminance signal is input to the A / D converter 31, the frequency overlap information detection unit 32 transmits the video signal proxy frequency. The overlapping information recording section 25 detects the frequency overlapping information. Next, the frequency unfolding unit 33 unfolds the frequency overlapped signal according to the frequency overlapping information detected by the frequency overlapping information detecting unit 32. The unfolded signal is then restored to the original signal via the adaptive re-emphasis section 34 and outputs the desired luminance signal through the D / A converter section 35.

Next, although not shown in FIG. 2B, the composite video signal generator 36 synthesizes the color signal from the color signal processing unit for processing the reproduced color signal and the luminance signal to output the composite video signal Y + C.

Thus, when the video signal recorded by the recording circuit of the existing video signal recording and reproducing apparatus as shown in FIG. 1A is reproduced by the reproducing circuit of the improved video signal recording and reproducing apparatus as shown in FIG. 2B. Since the recorded video signal is passed through the improved video signal reproduction process of unfolding by the frequency unfolding unit 33, the original video signal cannot be reduced.

As a result, the degree of original recording when a video signal recorded using a conventional video signal recording and reproducing apparatus is reproduced using the system disclosed in the 07 / 0769,029 filed on August 17, 1990 of the present applicant. It has been pointed out that the full resolution between different video signal recording and reproducing apparatus methods cannot be maintained since such resolution cannot be obtained.

Therefore, the present invention has been made to solve the above problems, and maintains compatibility of video signals recorded by different video signal recording methods on the reproducing circuit side of the improved video signal recording and reproducing apparatus to which the circuit of the present invention is applied. By adding a reproducible circuit, a single video signal recording and reproducing apparatus maintains compatibility at the time of reproducing video signals on video tapes recorded by different video signal recording methods on a screen as they are. An object thereof is to provide a luminance signal reproduction processing circuit.

Therefore, in order to achieve the above object, the present invention records the luminance signal and the synchronization signal through an adaptive de-emphasis unit, a frequency folding unit, and a frequency overlapping information recording unit when recording the video signal on the image tape, and reproduces the frequency signal when reproducing. A luminance signal reproducing circuit of a video signal reproducing apparatus, which reproduces through an information detecting section, a frequency unfolding section, and an adaptive re-emphasis section, and reproduces a video signal of a predetermined full bandwidth recorded on a recording medium having a limited bandwidth. A luminance signal input unit to which a luminance signal is input; A frequency overlapping information detection unit which receives the brightness signal and the synchronization signal supplied from the brightness signal inputting unit and detects whether the frequency overlapping information is carried on the synchronization signal; A first selector for selectively supplying a luminance signal in accordance with a detection result from the frequency overlapping information detector; An improved method signal processor for processing a luminance signal by an improved method when frequency overlap information exists according to a detection result from the frequency overlap information detector; An existing method signal processor for processing a signal according to an existing method when there is no frequency overlap information according to a detection result from the frequency overlap information detection unit; A second selector which receives output signals from the improved method signal processor and the existing method signal processor and selects one signal according to a detection result from the frequency overlapping information detector; And a luminance signal output section for outputting a luminance signal in accordance with the signal supplied from the second selector.

In addition, the present invention provides a luminance signal reproduction method of a video signal reproduction method of reproducing a video signal of a predetermined full bandwidth pre-recorded on a recording medium having a limited bandwidth, wherein the reproduction signal is reproduced from the recording medium through a reproduction head. Processing and inputting an image signal as a luminance signal in a standard luminance signal regenerator; detecting whether frequency input information is included in the input luminance signal; and in accordance with the frequency overlap information, among the processing routes of the luminance signal. And selecting one of the processed luminance signals according to the processing route of the selected luminance signal and selecting and outputting one of the processed luminance signals according to the frequency overlapping information. The luminance signal of the video tape recorded by the conventional video signal recording method is transferred to the improved recording / playback apparatus. Maintaining compatibility and provides a luminance signal reproducing method for maintaining compatibility between different video playback system characterized in that the reproduction.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

According to FIG. 3, the circuit for reproducing the luminance signal interchangeably between different image systems according to the present invention is characterized by the standard luminance of the image signal reproduced through the reproduction head from the image tape not shown on the surface even in the luminance signal input unit 70. The reproduction unit reproduces only the luminance signal, performs A / D conversion, and corrects the time axis. Next, the frequency overlap information detection unit 80 detects whether there is frequency overlap information in the luminance signal output from the brightness signal input unit 70.

Next, the de-emphasis unit 81 may be provided at the front end of the luminance signal input unit 70. In this embodiment, the de-emphasis unit 81 is provided at the rear end of the frequency overlap information detection unit 80, thereby providing the frequency overlap information detection unit 80. The high frequency component of the luminance signal that has passed is attenuated. The de-emphasized signal in the de-emphasis 81 is supplied to the first selector 82 via the reproduction equalization amplifier 85. In addition, the first selecting unit 82 selects and outputs a luminance signal to the improved luminance signal processing unit 100 when frequency overlapping information is detected according to the detection result from the frequency overlapping information detecting unit 80, and frequency overlapping information. If is not detected, the luminance signal is selectively outputted to the existing luminance signal processing unit 90.

Next, the signal processed by the improved luminance signal processor 100 and the signal processed by the existing luminance signal processor 90 are supplied to the second selector 200.

The second selector 200 according to the detection result from the frequency overlapping information detection unit 80, the signal supplied from the existing luminance signal processing unit 90 and the improved luminance signal processing unit 100 increases one signal. Outputs a selection.

Next, the luminance signal output unit 300 receives the output from the second selector 200 and outputs the luminance signal.

The operation of the luminance signal reproducing processing circuit which maintains compatibility at the time of reproducing between the signal recording and reproducing methods between different video systems according to the present invention having the above-described configuration will be described in detail with reference to FIG.

According to FIG. 4, in the case of reproducing the image tape recorded by the conventional method in the improved image signal recording and reproducing apparatus to which the circuit of the present invention is applied, the reproduced video signal is not shown in the drawing, After being separated into luminance signals, the luminance signals Y are converted into digital signals through the A / D changing section 71, and the digitally converted signals are regularly aligned via the time axis correcting unit (TBC) 75. After that, both the data signal and the synchronization signal are supplied to the frequency overlap information detection unit 80. In this case, the data signal refers to the luminance signal and the synchronization signal refers to the composite synchronization signal. The frequency overlapping information detection unit 80 detects whether or not frequency overlapping information exists in the composite synchronization signal. Here, the frequency overlapping information may be a pulse in which the insertion position is slightly changed for each field of the luminance signal. This pulse can be any type of pulse, such as an impulse or a square wave pulse. In addition, this frequency overlapping information may be a code word in which an insertion position inserted on the luminance signal is fixed at a constant. At this time, since the luminance signal passing through the frequency overlapping information detecting unit 80 is a pre-emphasized signal during recording, the high frequency component is attenuated by the de-emphasis unit 81. The de-emphasis unit 81 was located in front of the A / D conversion unit 31 as shown in FIG. 2B in U.S. Patent Application No. 07 / 569,029 dated August 17, 1990, but is preferred. In the embodiment, the frequency overlapping information detection unit 80 is located at the rear end.

In addition, the luminance signal de-emphasized by the de-emphasis unit 81 is supplied to the first selector 82 via the reproduction equalizer 85, and the first selector 82 is the frequency overlapping information detector 80. In accordance with the detection result of 1), one of the reproduction processing routes to be processed the luminance signal input from the de-emphasis unit 81 through the reproduction equalizer 85 is selected. When the input luminance signal is the luminance signal recorded by the conventional method, the first selector 82 attenuates the noise in the still image in the memory unit 91 and then supplies it to one end of the second selector 200. .

In the case of the video signal recorded by the improved method, the frequency unfolding unit 101 is supplied. Here, the existing luminance signal processing unit 90 of FIG. 3 includes the memory 91 as shown in FIG. 4 to form the existing luminance signal processing route, and the improved luminance signal processing unit 100 of FIG. As shown in FIG. 4, the frequency unfolding unit 101, the memory 91, the spatial reconstruction unit 102, the compound luminance signal generator 103, and the adaptive peaking re-emphasis unit 104 are improved. The luminance signal processing route is formed.

Therefore, according to the present invention, the frequency video information recording and reproducing apparatus reproduces the brightness signal recorded by the conventional method in the improved video signal recording / reproducing apparatus. After detecting whether it has been recorded by the controller, the selection means decides whether to use the conventional signal processor or the improved signal processor according to the detection result.

On the other hand, when frequency overlapping information is detected by the frequency overlapping information detecting unit 80, the first selector 82 supplies the brightness signal to the frequency unfolding unit 101, and according to the method of the improved luminance signal processing route. To process

The frequency unfolding unit 101 expands the frequency-overlapping video signal, removes the unfolded luminance signal from the memory 91 which removes the frequency-folding carrier in the still picture, and removes the frequency-folding carrier in the moving picture, and reconstructs the contour correction signal. The facial reconstruction unit 102 is supplied. Thereafter, the luminance signals supplied from the memory 91 and the spatial reconstruction unit 102 are supplied to the composite luminance signal generator 103. In the composite luminance signal generating section 103, although not shown in the drawing, the memory section 91 and the spatial reconstruction section 102 according to the motion data of the motion signal separated from the color signal processing and the motion signal processing. The signal supplied from the synthesizer is synthesized and supplied to the adaptive peaking re-emphasis unit 104. The adaptive peaking re-emphasis unit 104 restores the high frequency component to the original signal and supplies it to the other end of the second selection unit 200. The second selector 200 selects one of the signals supplied from the memory unit 91 and the adaptive peaking re-emphasis unit 104 according to the frequency overlapping information detection signal supplied from the frequency overlapping information detecting unit 80. The selected signal is supplied to the luminance signal output unit 300. The luminance signal output unit 300 includes an oversampling filter 301 and a D / A converter 302 and outputs an analog converted signal.

The oversampling filter 301 serves to increase the sampling rate in order to facilitate the conversion of the digital signal into analog signal processing.

In this embodiment, the circuit for reproducing the luminance signal interchangeably between different image systems is described only for the luminance signal processing circuit.

However, since the color signal processing unit and the copper signal processing unit relating to the circuits maintaining compatibility during the reproduction processing are the same as the signal processing route of the improved video signal recording and reproduction system, the description thereof is omitted in this embodiment.

That is, in this embodiment, only the luminance signal processing route is described in connection with detecting the frequency overlapping information inserted in the synchronization signal included in the luminance signal of the composite video signal reproduced from the image tape.

As described above, the circuit for reproducing the luminance signal interchangeably between different image systems is connected to the improved luminance signal processing unit in the VCR to which the circuit according to the present invention is applied, so that the image signal recorded by the existing VCR is compatible. Can play. Thus, video signals recorded by different VCRs can be reproduced interchangeably in the improved VCR without degrading the resolution of the recorded image in the recording process.

[Scope of Claim]

One.

Claims (10)

An adaptive de-emphasis section, a frequency folding section and a frequency overlapping information recording section for recording the luminance signal and the synchronization signal, and a frequency overlapping information detecting section, the frequency unfolding section and the adaptive re-emphasis section for reproducing the luminance signal and the synchronization signal. A circuit for reproducing a luminance signal interchangeably between different video systems in a video signal reproducing apparatus for reproducing a video signal of a predetermined full bandwidth pre-recorded on a recording medium having a limited bandwidth in a video signal recording and reproducing apparatus. A luminance signal input section into which said circuit is inputted; A frequency overlapping information detection unit which receives the brightness signal and the synchronization signal supplied from the brightness signal inputting unit and detects whether the frequency overlapping information is carried on the synchronization signal; A first selector for selectively supplying a luminance signal in accordance with a detection result from the frequency overlapping information detector; An improved luminance signal processing unit for processing the luminance signal by an improved image signal processing method when the frequency overlapping information detection unit detects the frequency overlapping information; An existing luminance signal processor for processing a luminance signal by an existing image signal processing method when the frequency overlap information detection unit detects that the frequency overlap information does not exist; A second selector which receives an output signal from the improved luminance signal processor and the existing luminance signal processor according to a detection result from the frequency overlapping information detector and selects one signal; And a luminance signal output unit for outputting a luminance signal supplied from said second selector. The luminance signal reproduction processing circuit for maintaining compatibility during reproduction between different image systems. The de-emphasis unit is connected between the frequency overlapping information detecting unit and the first selection unit when the de-emphasis unit for attenuating the high frequency component of the luminance signal is provided in front of the luminance signal input unit. A luminance signal reproduction processing circuit which maintains compatibility during reproduction between different image systems. 2. The apparatus of claim 1, wherein the improved luminance signal processing section comprises: a frequency unfolding section for releasing the overlapping frequency overlapped luminance signal supplied from the first selection section; The motion signal included in the video signal is received through the memory unit for removing the frequency folding carrier when the image is canceled and the spatial reconstruction unit for removing the frequency folding carrier and reconstructing the contour correction signal. A composite luminance signal generator for generating a composite luminance signal in accordance with data; And an adaptive peaking re-emphasis unit for restoring the high frequency component of the luminance signal supplied from the complex luminance signal generation unit back to the original signal. 4. The luminance of claim 3, wherein the existing luminance signal processor comprises a memory unit which receives a de-emphasized luminance signal supplied from the first selector and attenuates noise. Signal reproduction processing circuit. 2. The luminance signal reproduction processing circuit according to claim 1, wherein the first selector is composed of a switching element or a far-plexer. 6. The luminance signal reproduction processing circuit according to claim 5, wherein the second selector is constituted by a far multiplexer. A method of reproducing a luminance signal interchangeably between different video systems when reproducing a video signal of a predetermined full bandwidth previously recorded on a recording medium having a limited bandwidth, the video signal reproduced from the recording medium through a playback head. Inputting the processed luminance signal in a standard luminance signal reproducing processor, detecting whether frequency input information is included in the input luminance signal, and processing the luminance signal according to the frequency overlap information. Selecting one, processing the luminance signal according to the processing route of the selected luminance elongation, and selecting and outputting one of the processed luminance signals according to the frequency overlapping information. Compatibility of luminance signals on videotape recorded by video signal recording system Whether and to maintain the compatibility between different video playback system, characterized in that for reproducing the luminance signal reproduction processing circuit. 8. The method of claim 7, wherein when the frequency overlapping information is detected in the frequency overlapping information detection process, the brightness signal processing step includes: unfolding a high frequency component of the frequency-overlapping brightness signal at the low end of the brightness signal; Generating a complex luminance signal by receiving a signal from which a folding carrier is removed at a still image and a spatial reconstruction unit which removes a frequency folding carrier at a moving image and reconstructs a contour correction signal, and generates a high luminance component of the complex luminance signal. And an adaptive peaking re-emphasis step of recovering the signal. 8. The method of claim 7, wherein when the frequency overlapping information is not detected in the frequency overlapping information detection process, the brightness signal processing step includes attenuating noise through a memory device. 8. The method of claim 7, wherein if there is no de-emphasis process for attenuating high frequency components of the reproduced luminance signal before inputting the reproduced luminance signal, the de-emphasis process includes the frequency overlapping information detection process and the luminance. A luminance signal reproduction method characterized in that it is inserted between signal processing route selection processes.